Improved tool-rest for grindstones



"UNrrED STATES". PATENT Ormea WV. H. STRAHAN, OF PHILADELPHIA,PENNSYLVANIA.

IMPROVED` TOOL-REST FOR GRINDSTONES.

Specification forming part of Letters Patent No. 58,504, dated October3, 1855.

To all whom t may concern:

Be it knoWntha-t I, W. H. STRAHAN,ofPhila delphia, Pennsylvania, haveinvented an Improved Grindstone-Rest; and I do hereby declare thefollowing to be a full, clear, and exact description ofthe same,reference being had to the accompanying drawings, and to the letters ofreference marked thereon.

My invention consists of a rest constructed and secured in front of agrindstone substantially in the manner described hereinafter, so

as to afford facilities for grinding tools and other objects, andespecially for the grinding of drilling-tools, which can be accomplishedwith the greatest accuracy by the aid of my invention.

In order to enable others skilled in the art to make and useniyi'nvention, [will now proceed to describe its construction andoperation.

On reference tothe accompanying drawings, which form a part of thisspecification, Figure l is a side viewof myimproved grindstone-rest;Fig. 2, an end view, looking in the `direction of the arroW,Fi g. 1;Fig. 3, a plan View; and Figs. 4, 5, and 6, portions of the apparatus.

Similar letters refer to similar parts throughout the several views.

A is a foundationplate secured to the trough of a grindstone, or to anystationary object in front of the same, and to this plate is secured anadjustable plate, B, in the peculiar manner describedhereinafter.l Athird plate, D, is secured by bolts a to the plate B, in which areelongated openings for admitting the heads and stems of the said bolts,`the latter serving as guides for and permitting (when the nuts areloose) the free lateral adjustment only of the plate D.

E is a bar, at each end of which is a journal, c, adapted to a suitablebox, d, the boxes being attached to or forming a part of the plate l),and one of the journals of this bar projecting beyond its box for thepurpose of receiving an arm, F, the object of which will be renderedapparent hereinafter. To the bar E is secured an oblique arm, Gr, towhich a block, H, is iitted snugly, but so as to move to and fro freely,and on the same arm a collar, H', can be moved to and fro freely, andsecured, after adjustment, by a set-screw, h..

I is a guard having a beveled edge, 1'., and two langes,j j, the latterembracing the bar E, on which the said plate can be moved to an d fro,there being in the under side ofthe bar an elongated recess, a, (seeFig. 4,) for the reception ofthe head of a bolt, b, thc stein of whichprojects through an oblong slot in the bar, and through an opening inthe ilangej of the guard, the end of the bolt being furnished with asuitable nut, c.

It will be seen that the opening min the flange, through which the stemof the bolt passes, is partly horizontal and partly vertical, and that adog, a, is hung to the side of the ange, this dog being the means, whendepressed, of maintaining the stem of the boltin the horizontal portionof the opening m, and,

when elevated, permitting the bolt to be so moved that its stem willcoincide with the vertical portion of the opening, when the guard I maybe removed from the bar E.

Through the arm F, previously alluded to, passes a pin, q, into one orother of the holes t, Fig. 8, in the end of the plate l), so that thebar can be adjusted to different inclinations.

The mode of adjusting the apparatus on and securing it to thefoundation-plate A is as follows: It will be observed that the plate Bis beveled at its opposite edges, and that a clamping-plate, K, havingbeveled ribs 7c, Fig. l, is adjusted to each end of the said plate, eachclamping-plate having a beveled rib, a, Fig. 2, adapted to thebevelededge of the foundationplate A. In portions x of one of thebeveled edges of the plate are cut a series of notches for the receptionof a projection, y, Fig. 6, on one of the beveled ribs 7c of eachclampingplate K, the other rib of which is furnished with a set-screw,p, to bear against the edge of the plate B. The two clamping-plateshaving been so adjusted that their beveled edges u shall bear, that ofone plate against one bev eled edge and that of the other clampingplateagainst the opposite beveled edge of thefoundation-plate A, and theprojection y of the clamping-plates fitting in the notches a of theplate B, the set-screws pare turned so as to force one end of eachclamping-plate inward in the direction of the arrow, Fig. 6; for thismovement of the clamping-plate must be the result of tightening thescrew, owing to its position in relation to that of the projection y.The tight ening of the two screws will consequently result in thefoundation-plate being securely embraced by and between the two clamping-platcs, which, at the same time, secure the plate B to thefoundation-plate A.

After loosening the screws p, the entire rest may be adjusted to andfrom the grindstone, as well as laterally, at pleasure.

In the present instance the rest is arranged for grinding an ordinarydrilling-tool, M, the

square end of the drill resting in the angular recess e of the slidingblock H, and the cutting end resting on the bar E, one corner of thecutting-edge bearing against the inclined edge of the adjustable guardI. ,Necessary force is applied to the block H to push the drill forwardagainst the'stone, which is shown by red lilies, and during the grindingof the first cutting-edge of the drill the collar H must remain loose onthe oblique' arm Gr, and when the first edge has been ground to theextent desired, the collar must be so adjusted as to bear against theface of the block H, and .there secured by the set-screw It. After thisthe drill is reversed, its square end adjusted to the angle of therecess e', as before, and the block l H pushed forward, brin ging thesecond cuttingedge against the grindstone, care being taken to maintainthe corner of the tool in contact with the inclined edge z' of theadjustable guard I. When the drill has been pushed forward so that thesliding block H is in contact withl the collar H, the grinding of thedrill is' complete, and its point is certain to be central with thesquare end. The importance of this feature of myinvention will bereadilyunderstood by those familiar with drilling-tools, which 'havehitherto been ground without the aid of any appliances to insure acentral cuttingpoint.

As the arm Gr may be elevated and lowered at pleasure, and the barEturned'in its bearings and secured, after adjustment, by means of thepin q, it will be evident that both arm and bar may be arranged at suchan angle that the proper bevel will be imparted to the eutting-edges ofthe drill.

It will be seen, on reference to Fig. 2, that the bar E is graduated atthe point x. These graduations are such in respect to the guard .y

I that on adjusting the latter to a given mark it will indicate theproper position of the guard for grinding a drill of a given size.

After raising the dog a, Figs. 2 and 5, the adjustable guard I may beremoved from the bar E, and the oblique arm may be detached ,from thelatter, when the said bar E aords a suitable rest in grinding chiselsand other tools and objects.v

If desired, the bar E may be made perma.

nent and the arm G may be hinged to the said bar, so as to be raised orlowered atpleasure.

I claim as my invention and desire to secure by Letters Patent- 1. Thecombination of the adjustable foundation-plate A, plate B, theadjustable plate D, and bar E.

2. The combination of the bar E, its adjustable guard I, arm G, movableblock H, and ad-I In testimony whereof I have signed my name to thisspecification in the presence of two subscribing witnesses.

W. H. STRAHAN.

Witnesses C. B. PRICE, H. HoWsoN.

